[MM-67135] show premade themes when custom themes are disabled (#35540)

webapp/channels/src/components/user_settings/display/user_settings_theme/user_settings_theme.test.tsx

@@ -64,6 +64,27 @@ describe('components/user_settings/display/user_settings_theme/user_settings_the
         expect(requiredProps.actions.saveTheme).toHaveBeenCalled();
     });
 
+    it('should show premade themes when custom themes are disabled', () => {
+        const props = {
+            ...requiredProps,
+            selected: true,
+            allowCustomThemes: false,
+        };
+
+        renderWithContext(
+            <UserSettingsTheme {...props}/>,
+        );
+
+        // Premade theme chooser should still be rendered
+        expect(screen.getByText('Save')).toBeInTheDocument();
+        expect(screen.queryByLabelText('Premade Themes')).not.toBeInTheDocument();
+        expect(screen.queryByLabelText('Custom Theme')).not.toBeInTheDocument();
+
+        // The premade themes should be visible (theme thumbnails are rendered)
+        const premadeThemes = document.querySelectorAll('.premade-themes');
+        expect(premadeThemes.length).toBeGreaterThan(0);
+    });
+
     it('should deleteTeamSpecificThemes if applyToAllTeams is enabled', async () => {
         const props = {
             ...requiredProps,

webapp/channels/src/components/user_settings/display/user_settings_theme/user_settings_theme.tsx

@@ -238,6 +238,8 @@ export default class ThemeSetting extends React.PureComponent<Props, State> {
                         </ExternalLink>
                     </div>,
                 );
+            } else {
+                inputs.push(premade);
             }
 
             let allTeamsCheckbox = null;